Line item editor issue, where contribution Total Amount includes the Tax amount twice

Issue Description: When creating a membership the total amount shown on the line editor section is adding the tax amount twice as you can see here - https://nimb.ws/lMASmR

Replication Steps: https://nimb.ws/AfUNvV

Environment: Tested on clean CiviCRM v5.7.5 and Line Item Editor v2.0.

Recording this here as think this extension should be part of core. Please let me know thoughts?

Edited May 10, 2019 by madura

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